Next Article in Journal
Small Peptides Able to Suppress Prostaglandin E2 Generation in Renal Mesangial Cells
Previous Article in Journal
Synthesis, Structural Characterization, Antimicrobial Activity, and In Vitro Biocompatibility of New Unsaturated Carboxylate Complexes with 2,2′-Bipyridine
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Molecules
Volume 23
Issue 1
10.3390/molecules23010159
molecules-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Structural Determination of Ruthenium Complexes Containing Bi-Dentate Pyrrole-Ketone Ligands

by
Ya-Wen Tsai
1,
Yun-Fan Chen
1,
Yong-Jie Li
1,
Kuan-Hung Chen
1,
Chia-Her Lin
2 and
Jui-Hsien Huang
1,*
1
Department of Chemistry, National Changhua University of Education, Changhua 50058, Taiwan
2
Department of Chemistry, Chung-Yuan Christian University, Chun-Li 320, Taiwan
*
Author to whom correspondence should be addressed.
Molecules 2018, 23(1), 159; https://doi.org/10.3390/molecules23010159
Submission received: 19 December 2017 / Revised: 6 January 2018 / Accepted: 12 January 2018 / Published: 13 January 2018
(This article belongs to the Section Inorganic Chemistry)
Browse Figures
Versions Notes

Abstract

:
A series of ruthenium compounds containing a pyrrole-ketone bidentate ligand, 2-(2′-methoxybenzoyl)pyrrole (1), have been synthesized and characterized. Reacting 1 with [(η6-cymene)RuCl2]2 and RuHCl(CO)(PPh3)3 generated Ru(η6-cymene)[C4H3N-2-(CO-C6H4-2-OMe)]Cl (2) and {RuCl(CO)(PPh3)2[C4H3N-2-(COC6H4-2-OMe)]} (3), respectively, in moderate yields. Successively reacting 2 with sodium cyanate and sodium azide gave {Ru(η6-cymene)[C4H3N-2-(CO-C6H4-2-OMe)]X} (4, X=OCN; 5, X=N3) with the elimination of sodium chloride. Compounds 2–5 were all characterized by 1H and 13C-NMR spectra and their structures were also determined by X-ray single crystallography.

Graphical Abstract

1. Introduction

Ruthenium compounds [1,2,3] containing varieties of ligands, such as cymene [4,5], phosphine [6] NHC [7], keto-amine [8,9], and Schiff-base [10,11], represent an important chemical series on the field of medicinal chemistry [12,13,14,15] and catalytic transfer hydrogenation [16,17,18] etc. Finely tuned ruthenium complexes can be achieved by changing the coordinating ligands. Therefore, by combining suitable ruthenium complexes with organic ligands and studying their structural geometries may shed some light on the understanding of the functions of these ruthenium complexes.
Among of these ruthenium compounds, [(η6-cymene)RuCl2]2 [19] and RuHCl(CO)(PPh3)3 [20] are two important starting materials for synthesizing corresponding ruthenium compounds due to their versatile applications [21,22,23,24]. Pyrrole represents an important heterocyclic compound for forming materials such as hemes and porphyrinc [25,26], ion-receptors [27,28], bio-active products [29,30,31], and light-harvesting pigments [32], etc. Its related compound, 2-(2′-methoxybenzoyl)pyrrole (1) [33,34,35], a multi-dentate ligand, was isolated from the mycelia extract [36] and exhibits bio-activity [37,38].
Here we report the synthesis and structural characterization of a series of ruthenium compounds containing the multidentate pyrrole-ketone ligand. The successive reacting of these ruthenium complexes with sodium salts of NaOCN and NaN3 is also reported. These compounds were structurally determined in order to understand their steric geometries for further applications.

2. Results and Discussion

2.1. Synthesis and Characterization

A series of ruthenium compounds containing 2-(2′-methoxybenzoyl)pyrrole (1) was synthesized and characterized. A reaction scheme of 1 with [(η6-cymene)RuCl2]2 and RuHCl(CO)(PPh3)3 is shown in Scheme 1. Reacting [(η6-cymene)RuCl2]2 with two equivalents of 1 in methanol solution at room temperature in the presence of sodium bicarbonate gave a 32.0% yield of Ru(η6-cymene)[C4H3N-2-(CO-C6H4-2-OMe)]Cl (2). The 1H-NMR spectrum of 2 showed four doublets in the range of δ 5.62~5.35 representing the arene CH protons of the cymene fragment. Similarly, while reacting 1 with RuHCl(CO)(PPh3)3 in toluene under refluxing and work-up, the resulting product {RuCl(CO)(PPh3)2[C4H3N-2-(COC6H4-2-OMe)]} (3) was prepared in a 66.9% yield along with the elimination of one equivalent of hydrogen molecules. The 1H-NMR spectrum of 3 showed the pyrrole CH chemical shifts at δ 5.50, 5.59, and 6.65. Due to the weak hydrogen bonding, the isopropyl fragment showed two doublets in the 1H-NMR spectrum representing the slow C-C bond rotation of the isopropyl and the cymene phenyl ring. The 13C-NMR spectra of 3 showed two chemical shifts at δ 205.6 and 183.4, assigned as the carbon of C≡O and C=O, respectively [39,40]. The IR spectrum of 3 also showed a strong absorption band at 1942 cm−1 representing the stretching frequency of C≡O [41,42].
Successively replacing the chloride anion of 2 with sodium salts of NaX in methanol resulted in new ruthenium compounds {Ru(η6-cymene)[C4H3N-2-(CO-C6H4-2-OMe)]X} (4, X=OCN; 5, X=N3). Compounds 4 and 5 were both characterized by 1H and 13C-NMR spectra and showed patterns similar to those of Compound 2, indicating that the electronic properties around the ruthenium atom was not affected by the coordinated mono-anionic ligands.

2.2. Molecular Geometries of Compounds 2–5

Single-crystals of Compounds 2–5 for X-ray diffraction analysis were obtained from either methanol or THF saturated solution at −20 °C. The summary of the X-ray crystal data and selected bond lengths and angles are shown in Table 1 and Table 2, respectively. The molecular geometries of 2–5 are depicted in Figure 1, Figure 2, Figure 3, Figure 4. The molecular geometry of 2 could be described as a three-legged piano stool with the nitrogen atom of the pyrrole, the oxygen atom of the carbonyl atoms, and the chloride atom forming the three legs and the cymene ring acting as the stool plane. The bond length of the ruthenium atom to the center of the cymene ring is 1.6598(1) Å, relatively close to the bond lengths of published ruthenium-cymene compounds [41,42]. It is interesting to note that the methine proton (H8) of the cymene ring was close to the oxygen atom (O2) of the methoxy group of ligand 1, with a bond length of 2.511 Å, which is assumed to be a weak hydrogen bonding between the H8 and O2 atoms [43].
The molecular geometry of 3 is shown in Figure 2 and the THF molecule was omitted for clarity. It can be described as a distorted octahedral with three axes of Cl(1)-Ru(1)-N(1), O(1)-Ru(1)-C(50), and P(1)-Ru(1)-P(2) with angles of 166.70(14)°, 172.9(2)°, and 177.38 (5)°, respectively. The ligand 1 binds to the ruthenium atom in an acute chelating angle of N(1)-Ru(1)-O(1) at 78.32(16)°. The bond lengths of Ru(1)-C(50) and C(50)-O(4) are 1.845(7) Å and 1.128(8) Å, respectively, indicating a slight back bonding of the ruthenium atom to the carbonyl and the longer C≡O bond. The results are in agreement with reported trans-RuCl(CO)(PPh3)2(bidentate) structures [44,45,46,47,48].
The molecular geometry of 4 can also be described as a three-legged piano stool geometry, as shown in Figure 3. The bond length from the ruthenium atom to the center of the cymene ring is at ca. 1.667 Å. The ambi-dentate NCO ligand was bound to the ruthenium atom at the N-end. Similar ruthenium cymene-NCO structures have been reported in the literature [49,50]. The bond lengths of ruthenium to the cyanate-N atom as well as N=C and C=O are all consistent with the results in the literature.
The pale orange crystals of 5 were obtained from a saturated methanol solution at −20 °C. The molecular structure of 5 is shown in Figure 4 and its geometry is similar to that of 2. It can also be described as a three-legged piano stool geometry with the azide and pyrrolyl nitrogen atoms and carboxyl oxygen atom taking the three leg positions and the cymene acting as the planar surface. The bond length of O(2)-H(8) was ca. 2.868 Å, indicating a very weak or no hydrogen bonding effect. Ru(cymene)azido compounds have been reported in the literature [51,52,53,54]. For 5, the bond lengths of Ru(1)-N(1), N(1)-N(2), and N(2)-N(3) were 2.109(2) Å, 1.204(3) Å, and 1.157(3) Å, respectively and these data are consistent that reported in the literature.

3. Experimental Section

3.1. General Consideration

All reactions were performed under a nitrogen atmosphere using standard Schlenk techniques or in a glove box. Toluene was dried by refluxing over sodium benzophenone ketyl. CH2Cl2 was dried over P2O5. All solvents were distilled and stored in solvent reservoirs that contained 4-Å molecular sieves and were purged with nitrogen. The 1H and 13C-NMR spectra were recorded using a Bruker Avance 300 spectrometer and the chemical shifts were recorded in ppm relative to the residual protons of CDCl3 (δ = 7.24, 77.0 ppm). Elemental analyses were performed using a Heraeus CHN-OS Rapid Elemental Analyzer at the Instrument Center of the NCHU. Ligands [33,34,35] 1 and [Ru(η6-p-cymene)Cl2]2 were prepared using a modified procedure [19].

3.1.1. Synthesis of the Ligand [C4H3NH-2-(CO-C6H4-2-OMe)] (1)

A Schlenk flask charged with pyrrole (0.38 g, 5.7 mmol) and 15 mL of toluene was added to equimolar MeMgBr (3.0 M, 1.9 mL) at 0 °C. The resulting solution was then refluxing for 30 min under nitrogen. The color changed from bright yellow back to orange. Methoxybenzoyl chloride (0.97 g, 5.7 mmol) was then added to the resulting solution at room temperature and the solution color changed back to yellow again. Ammonium chloride water solution was added to the solution after 30 min and the combing solution was extracted with diethyl ether (10 mL × 3). The extraction was dried over MgSO4 and volatiles were removed to give ligand 1 in a 63.0% yield (0.727 g). 1H-NMR (CDCl3): 3.80 (s, 3H, OMe), 6.24 (m, 1H, pyr CH), 6.62 (m, 1H, pyr CH), 6.99 (m, 2H, phenyl CH), 7.10 (m, 1H, pyr CH), 7.42 (m, 2H, phenyl CH), 10.12 (s, 1H, pyr NH).

3.1.2. Synthesis of Compound {Ru(η6-cymene)[C4H3N-2-(CO-C6H4-2-OMe)]Cl} (2)

A methanol solution (10 mL) of 1 (0.20 g, 0.99 mmol) and [Ru(η6-p-cymene)Cl2]2 (0.304 g, 0.50 mmol) in a 50 mL of flask was stirred for 1 h at room temperature. Sodium bicarbonate then was added into the solution and stirred for 3 h. The volatiles were removed under vacuum and the solid was extracted with methylene chloride and then solvent was removed again to give crude product of 2. The product was recrystallized from a methanol solution to generate 0.149 g of red brown crystals in a 32.0% yield. 1H-NMR (CDCl3): 1.21 (d, 3H, CHMe2), 1.23 (d, 3H, CHMe2), 2.30 (s, 3H, Me), 2.81 (sept, JHH = 7.2 Hz, 1H, CHMe2), 3.77 (s, 3H, OMe), 5.35 (d, JHH = 6.0 Hz, 1H, cymene CH), 5.40 (d, JHH = 6.0 Hz, 1H, cymene CH), 5.55 (d, JHH = 5.7 Hz, 1H, cymene CH), 5.62 (d, JHH = 5.7 Hz, 1H, cymene CH), 6.37 (m, 1H, pyr CH), 6.79 (m, 1H, pyr CH), 7.36 (m, 5H, phenyl C6H4 + pyr CH). 13C-NMR (CDCl3): 18.9 (cymene Me), 22.1 (cymene CHMe2), 22.8 (cymene CHMe2), 31.9 (cymene CHMe2), 55.9 (OMe), 79.3 (cymene CH), 81.8 (cymene CH), 82.0 (cymene CH), 83.5 (cymene CH), 98.4 (cymene Cipso), 100.5 (cymene Cipso), 111.8 (pyr CH), 116.1 (pyr CH), 120.4 (phenyl CH), 123.4 (phenyl CH), 125.5 (pyr Cipso), 131.4 (phenyl CH), 132.1 (phenyl CH), 141.8 (phenyl Cipso), 143.1 (pyr CH), 157.7 (phenyl Cipso), 186.7 (C=O). Anal. Calcd for C22H24ClNO2Ru: C, 56.11; H, 5.14; N, 2.97. Found: C, 56.08; H, 5.15; N, 3.36.

3.1.3. Synthesis of Compound {RuCl(CO)(PPh3)2[C4H3N-2-(COC6H4-2-OMe)]} (3)

A toluene solution (10 mL) of 1 (0.08 g, 0.40 mmol) and RuHCl(CO)(PPh3)3 (0.378 g, 0.40 mmol) in a 50 mL of flask was refluxed for 24 h under nitrogen. The volatiles were removed under vacuum and residue was washed with heptane to remove excess of PPh3. The resulting solid was recrystallized from a saturated THF solution at −20 °C to give 0.24 g of yellow crystals in a 66.9% yield. 1H-NMR (CDCl3): 3.31 (s, 3H, OMe), 5.50 (t, 1H, pyr CH), 5.59 (m, 1H, pyr CH), 6.20 (m, 1H, phenyl CH), 6.40 (m, 1H, phenyl CH), 6.65 (m, 2H, pyr + phenyl CH), 7.30 (m, 31H, PPh3 CH+ phenyl CH). 13C-NMR (CDCl3): 55.0 (OMe), 110.3, 117.3, 119.7, 123.0, 125.4, 126.6, 127.8, 127.9, 128.0, 128.3, 128.6, 128.7, 129.2, 129.5, 130.5, 130.9, 131.0, 131.2, 131.5, 132.2, 134.5, 134.6, 134.7,141.3, 142.6, 156.3, 183.4 (C=O), 205.6 (C≡O). Anal. Calcd for C49H40NO3P2ClRu: C, 66.13; H, 4.53; N, 1.57. Found: C, 66.01; H, 4.86; N, 1.53.

3.1.4. Synthesis of Compound {Ru(η6-cymene)[C4H3N-2-(CO-C6H4-2-OMe)](OCN)} (4)

A 25 mL Schlenk flask charged with 2 (0.117 g, 0.25 mmol), excess sodium cyanate and methanol (10 mL) was stirred at room temperature for overnight. Methanol was removed under vacuum and residue was extracted with methylene chloride (10 mL × 3). The methylene chloride was removed and residue was recrystallized from a methanol solution at −20 °C to yield 0.045 g of orange crystals of 4 (38.1% yield). 1H-NMR (CDCl3): 1.20 (d, 3H, CHMe2), 1.22 (d, 3H, CHMe2), 2.25 (s, 3H, Me), 2.74 (sept, JHH = 6.9 Hz,1H, CHMe2), 3.77 (s, 3H, OMe), 5.32 (d, 2H, JHH = 6.3 Hz, cymene CH), 5.57 (d, JHH = 5.4 Hz, 1H, cymene CH), 5.62 (d, JHH = 5.4 Hz, 1H, cymene CH), 6.37 (m, 1H, pyr CH), 6.78 (m, 1H, pyr CH), 7.38 (m, 4H, phenyl C6H4 CH), 7.62 (t, 1H, pyr CH). Anal. Calcd for C23H24N2O3Ru: C, 57.70; H, 5.06; N, 5.86. Found: C, 57.70; H, 5.18; N, 6.04.

3.1.5. Synthesis of Compound {Ru(η6-cymene)[C4H3N-2-(CO-C6H4-2-OMe)](N3)} (5)

A 25 mL Schlenk flask charged with 2 (0.047 g, 0.10 mmol), excess sodium azide, and methanol (10 mL) was stirred at room temperature for overnight. Methanol was removed under vacuum and residue was extracted with methylene chloride (10 mL × 3). The methylene chloride was removed and residue was recrystallized from a methanol solution at −20°C to yield 0.026 g of orange crystals of 5 (53.8% yield). 1H-NMR (CDCl3): 1.23 (d, 3H, CHMe2), 1.25 (d, 3H, CHMe2), 2.27 (s, 3H, Me), 2.78 (sept, JHH = 6.9 Hz,1H, CHMe2), 3.80 (s, 3H, OMe), 5.32 (m, 2H, cymene CH), 5.53 (d, JHH = 6.0 Hz, 1H, cymene CH), 5.62 (d, JHH = 6.0 Hz, 1H, cymene CH), 6.43 (t, 1H, pyr CH), 6.82 (m, 1H, pyr CH), 7.38 (m, 5H, phenyl C6H4 + pyr CH). 13C-NMR (CDCl3): 18.4 (cymene Me), 22.5 (cymene CHMe2), 22.8 (cymene CHMe2), 31.2 (cymene CHMe2), 55.9 (OMe), 78.9 (cymene CH), 81.7 (cymene CH), 82.4 (cymene CH), 84.2 (cymene CH), 98.7 (arene C), 100.5 (Cipso),111.7 (pyr CH), 116.2 (pyr CH), 120.5 (phenyl CH), 123.7 (phenyl CH), 125.2 (Cipso), 131.6 (phenyl CH), 132.1 (phenyl CH), 142.1 (Cipso), 143.2 (pyr CH), 157.7 (Cipso), 187.2 (C=O). Anal. Calcd for C22H24N4O2Ru: C, 55.34; H, 5.07; N, 11.73. Found: C, 55.32; H, 5.09; N, 11.75.

3.2. X-ray Crystallography

Suitable crystals of Compounds 2–5 were attached to a fine glass fiber and mounted in goniostat for data collection. Data collections were performed at 150 K under liquid nitrogen vapor for all compounds. Data were collected on a Bruker SMART CCD diffractometer with graphite monochromated Mo-Kα radiation. No significant crystal decay was found. Data were corrected for absorption empirically by means of ψ scans. All non-hydrogen atoms were refined with anisotropic displacement parameters. For all the structures, the hydrogen atom positions were calculated and they were constrained to idealized geometries and treated as rigid where the H atom displacement parameter was calculated from the equivalent isotropic displacement parameter of the bound atom. An absorption correction was performed with the program SADABS [55] and the structures of both complexes were determined by direct methods procedures in SHELXS [56] and refined by full-matrix least-squares methods, on F2’s, in SHELXL [57]. All the relevant crystallographic data and structure refinement parameters are summarized in Table 1.

4. Conclusions

We have successfully employed a bidentate pyrrole-ketone ligand with ruthenium compounds to form a series of Compounds 2–5 and their structures were determined by X-ray single crystallography. A preliminary test of hydrogen transfer reactions of acetophenone and isopropyl alcohol using these ruthenium compounds showed low conversion. We are currently using Compounds 2–5 to investigate the catalytic activities of hydrogen transfer reactions toward varieties of ketones and alcohols and the hydroaminations of inter- and intra-molecular alkenes and alkynes.

Supplementary Materials

Tables for crystal data including H-bonding. Crystallographic data for the structures reported in this paper have been deposited with the Cambridge Crystallographic Data Centre as supplementary publications nos. CCDC-1567212-5 (Compounds 2–5). Copies of the data can be obtained free of charge on application to CCDC, 12 Union Road, Cambridge CB2 1EZ, UK (fax: +44-1223-336-033; e-mail: [email protected] or www: http://www.ccdc.cam.ac.uk).

Acknowledgements

The authors express their appreciation to the Ministry of Science and Technology, Taiwan for financial support (MOST 105-2113-M-018-005). We also thank the National Center for High-performance Computing for supporting the chemistry database searching.

Author Contributions

YWT, synthesizing and characterizing compounds; YFC, YJL, KHC, CHL, performed the crystal structures data collection and solving the structures; JHH designed the research and wrote the paper.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Dragutan, I.; Dragutan, V.; Demonceau, A. Editorial of special issue ruthenium complex: The expanding chemistry of the ruthenium complexes. Molecules 2015, 20, 17244–17274. [Google Scholar] [CrossRef] [PubMed]
  2. Storr, T. Ligand Design in Medicinal Inorganic Chemistry; John Wiley & Sons, Ltd.: Chichester, UK, 2014. [Google Scholar]
  3. Holder, A.A.; Lilge, L.; Browne, W.R.; Lawrence, M.A.W.; Bullock, J.L., Jr. (Eds.) Ruthenium Complexes: Photochemical and Biomedical Applications; Wiley-VCH: Weinheim, Germany, 2016. [Google Scholar]
  4. Weiss, A.; Berndsen, R.H.; Dubois, M.; Muller, C.; Schibli, R.; Griffioen, A.W.; Dyson, P.J.; Nowak-Sliwinska, P. In vivo anti-tumor activity of the organometallic ruthenium(II)-arene complex [Ru(η6-p-cymene)Cl2(pta)] (RAPTA-C) in human ovarian and colorectal carcinomas. Chem. Sci. 2014, 5, 4742–4748. [Google Scholar] [CrossRef]
  5. Clavel, C.M.; Păunescu, E.; Nowak-Sliwinska, P.; Griffioen, A.W.; Scopelliti, R.; Dyson, P.J. Discovery of a highly tumor-selective rrganometallic ruthenium(II)-arene complex. J. Med. Chem. 2014, 57, 3546–3558. [Google Scholar] [CrossRef] [PubMed]
  6. Sáez, R.; Lorenzo, J.; Prieto, M.J.; Font-Bardia, M.; Calvet, T.; Omeñaca, N.; Vilaseca, M.; Moreno, V. Influence of PPh3 moiety in the anticancer activity of new organometallic ruthenium complexes. J. Inorg. Biochem. 2014, 136, 1–12. [Google Scholar] [CrossRef] [PubMed]
  7. Kilpin, K.J.; Crot, S.; Riedel, T.; Kitchen, J.A.; Dyson, P.J. Ruthenium(II) and osmium(II) 1,2,3-triazolylidene organometallics: A preliminary investigation into the biological activity of ‘click’ carbene complexes. Dalton Trans. 2014, 43, 1443–1448. [Google Scholar] [CrossRef] [PubMed]
  8. Pettinari, R.; Pettinari, C.; Marchetti, F.; Clavel, C.M.; Scopelliti, R.; Dyson, P.J. Cytotoxicity of ruthenium–arene complexes containing β-ketoamine ligands. Organometallics 2013, 32, 309–316. [Google Scholar] [CrossRef]
  9. Pettinari, R.; Marchetti, F.; Pettinari, C.; Petrini, A.; Scopelliti, R.; Clavel, C.M.; Dyson, P.J. Synthesis, structure, and antiproliferative activity of ruthenium(II) arene complexes with N,O-chelating pyrazolone-based β-ketoamine ligands. Inorg. Chem. 2014, 53, 13105–13111. [Google Scholar] [CrossRef] [PubMed]
  10. Garza-Ortiz, A.; Maheswari, P.U.; Siegler, M.; Spek, A.I.; Reedijk, J. A new family of Ru(II) complexes with a tridentate pyridine Schiff-base ligand and bidentate co-ligands: Synthesis, characterization, structure and in vitro cytotoxicity studies. New J. Chem. 2013, 37, 3450–3460. [Google Scholar] [CrossRef]
  11. Chow, M.J.; Licona, C.; Wong, D.Y.Q.; Pastorin, G.; Gaiddon, C.; Ang, W.H. Discovery and investigation of anticancer ruthenium-arene Schiff-base complexes via water-promoted combinatorial three-component assembly. J. Med. Chem. 2014, 57, 6043–6059. [Google Scholar] [CrossRef] [PubMed]
  12. Allardyce, C.S.; Dyson, P.J. Ruthenium in medicine: Current clinical uses and future prospects. Platinum Metal. Rev. 2001, 45, 62–69. [Google Scholar]
  13. Zeng, L.; Gupta, P.; Chen, Y.; Wang, E.; Ji, L.; Chao, H.; Chen, Z.-S. The development of anticancer ruthenium(II) complexes: From single molecule compounds to nanomaterials. Chem. Soc. Rev. 2017, 46, 5771–5804. [Google Scholar] [CrossRef] [PubMed]
  14. Ronconi, L.; Sadler, P.J. Using coordination chemistry to design new medicines. Coord. Chem. Rev. 2007, 251, 1633–1648. [Google Scholar] [CrossRef]
  15. Dougan, S.J.; Sadler, P.J. The Design of Organometallic Ruthenium Arene Anticancer Agents. Chimia 2007, 61, 704–715. [Google Scholar] [CrossRef]
  16. Sheeba, M.M.; Tamizh, M.M.; Farrugia, L.J.; Endo, A.; Karvembu, R. Chiral (η6-p-Cymene)ruthenium(II) complexes containing monodentate acylthiourea ligands for efficient asymmetric transfer hydrogenation of ketones. Organometallics 2014, 33, 540–550. [Google Scholar] [CrossRef]
  17. Guo, R.; Lough, A.J.; Morris, R.H.; Song, D. Asymmetric hydrogenation of ketones catalyzed by ruthenium hydride complexes of a beta-aminophosphine ligand derived from norephedrine. Organometallics 2004, 23, 5524–5529. [Google Scholar] [CrossRef]
  18. Kalutharage, N.; Yi, C.S. Scope and mechanistic analysis for chemoselective hydrogenolysis of carbonyl compounds catalyzed by a cationic ruthenium hydride complex with a tunable phenol ligand. J. Am. Chem. Soc. 2015, 137, 11105–11114. [Google Scholar] [CrossRef] [PubMed]
  19. Benneth, M.A.; Smith, A.K. Arene ruthenium(II) complexes formed by dehydrogenation of cyclohexadienes with ruthenium(III) trichloride. J. Chem. Soc. Dalton Trans. 1974, 233–241. [Google Scholar] [CrossRef]
  20. Chatt, J.; Leigh, G.J.; Mingos, D.M.P.; Paske, R.J. Complexes of osmium, ruthenium, rhenium, and iridium halides with some tertiary monophosphines and monoarsines. J. Chem. Soc. A 1968, 2636–2641. [Google Scholar] [CrossRef]
  21. Allardyce, C.S.; Dyson, P.J.; Ellis, D.J.; Heath, S.L. [Ru(η6-p-cymene)Cl2(pta)] (pta = 1,3,5-triaza-7-phosphatricyclo-[3.3.1.1]decane): A water soluble compound that exhibits pH dependent DNA binding providing selectivity for diseased cells. Chem. Commun 2001, 1396–1397. [Google Scholar] [CrossRef]
  22. Adeniyi, A.A.; Ajibade, P.A. Development of ruthenium-based complexes as anticancer agents: Toward a rational design of alternative receptor targets. Rev. Inorg. Chem. 2016, 36, 53–75. [Google Scholar] [CrossRef]
  23. Clarke, M.J. Ruthenium metallopharmaceuticals. Coord. Chem. Rev. 2003, 236, 209–233. [Google Scholar] [CrossRef]
  24. Dyson, P.J. Systematic Design of a Targeted Organometallic Antitumour Drug in Pre-clinical Development. Chimia 2007, 61, 698–703. [Google Scholar] [CrossRef]
  25. Cox, M.; Lehninger, A.L.; Nelson, D.R. Principles of Biochemistry; Worth Publishers: New York, NY, USA, 2000. [Google Scholar]
  26. Shimizu, S. Recent advances in subporphyrins and triphyrin analogues: Contracted porphyrins comprising three pyrrole rings. Chem. Rev. 2017, 117, 2730–2784. [Google Scholar] [CrossRef] [PubMed]
  27. Kim, S.K.; Gross, D.E.; Cho, D.-G.; Lynch, V.M.; Sessler, J.L. N-Tosylpyrrolidine calix[4]pyrrole: Synthesis and ion binding studies. J. Org. Chem. 2011, 76, 1005–1012. [Google Scholar] [CrossRef] [PubMed]
  28. Maeda, H.; Bando, Y. Recent progress in research on anion-responsive pyrrole-based π-conjugated acyclic molecules. Chem. Commun. 2013, 49, 4100–4113. [Google Scholar] [CrossRef] [PubMed]
  29. Khajuria, R.; Dham, S.; Kapoor, K.K. Active methylenes in the synthesis of a pyrrole motif: An imperative structural unit of pharmaceuticals, natural products and optoelectronic materials. RSC Adv. 2016, 6, 37039–37066. [Google Scholar] [CrossRef]
  30. Bhardwaj, V.; Gumber, D.; Abbot, V.; Dhiman, S.; Sharma, P. Pyrrole: A resourceful small molecule in key medicinal hetero-aromatics. RSC Adv. 2015, 5, 15233–15266. [Google Scholar] [CrossRef]
  31. Al-Mourabit, A.; Zancanella, M.A.; Tilvi, S.; Romo, D. Biosynthesis, asymmetric synthesis, and pharmacology, including cellular targets, of the pyrrole-2-aminoimidazole marine alkaloids. Nat. Prod. Rep. 2011, 28, 1229–1260. [Google Scholar] [CrossRef] [PubMed]
  32. Trimm, H.H.; Hunter, W., Jr. Dyes and Drugs-New Uses and Implications; Apple Academic Press: Toronto, ON, Canada, 2011. [Google Scholar]
  33. Kanakis, A.A.; Sarli, V. Total synthesis of (±)-marinopyrrole A via copper-mediated N-arylation. Org. Lett. 2010, 12, 4872–4875. [Google Scholar] [CrossRef] [PubMed]
  34. Hughes, C.C.; Kauffman, C.A.; Jensen, P.R.; Fenical, W. Structures, reactivities, and antibiotic properties of the marinopyrroles A−F. J. Org. Chem. 2010, 75, 3240–3250. [Google Scholar] [CrossRef] [PubMed]
  35. Petruso, S.; Bonanno, S.; Caronna, S.; Ciofalo, M.; Maggio, B.; Schillaci, D. Oxidative halogenation of substituted pyrroles with Cu(II). Part IV. Bromination of 2-(2′-hydroxybenzoyl)pyrrole. A new synthesis of bioactive analogs of monodeoxypyoluteorin. J. Heterocycl. Chem. 1994, 31, 941. [Google Scholar] [CrossRef]
  36. Ghigo, G.; Ciofalo, M.; Gagliardi, L.; La Manna, G.; Cramer, C. The electronic spectra of 2-(2′-hydroxybenzoyl)pyrrole and 2-(2’-methoxybenzoyl)pyrrole: A theoretical study. J. Phys. Org. Chem. 2005, 18, 1099–1106. [Google Scholar] [CrossRef]
  37. Wang, H.-G.; Amin, S. Mcl-1 Modulating Compositions. Patent WO2013/112878 A1, 1 August 2013. [Google Scholar]
  38. Trisuwan, K.; Rukachaisirikul, V.; Sukpondma, Y.; Phongpaichit, S.; Preedanon, S.; Sakayaroj, J. Furo[3,2-h]isochroman, furo[3,2-h]-isoquinoline, isochroman, phenol, pyranone, and pyrone derivatives from the sea fan-derived fungus Penicillium sp. PSU-F40. Tetrahedron 2010, 66, 4484–4489. [Google Scholar] [CrossRef]
  39. Chen, T.; Li, H.; Qu, S.; Zheng, B.; He, L.; Lai, Z.; Wang, Z.-X.; Huang, K.-W. Hydrogenation of esters catalyzed by ruthenium PN3-pincer complexes containing an aminophosphine arm. Organometallics 2014, 33, 4152–4155. [Google Scholar] [CrossRef]
  40. Anaby, A.; Butschke, B.; Ben-David, Y.; Shimon, L.J.W.; Leitus, G.; Feller, M.; Milstein, D. B–H bond cleavage via metal–ligand cooperation by dearomatized ruthenium pincer complexes. Organometallics 2014, 33, 3716–3726. [Google Scholar] [CrossRef]
  41. Raja, M.U.; Gowri, N.; Ramesh, R. Synthesis, crystal structure and catalytic activity of ruthenium(II) carbonyl complexes containing ONO and ONS donor ligands. Polyhedron 2010, 29, 1175–1181. [Google Scholar] [CrossRef]
  42. Gusev, D.G.; Dolgushin, F.M.; Antipin, M.Y. Hydride, borohydride, and dinitrogen pincer complexes of ruthenium. Organometallics 2000, 19, 3429–3434. [Google Scholar] [CrossRef]
  43. Veljković, D.Z.; Janjića, G.V.; Zarić, S.D. Are C–H⋯O interactions linear? The case of aromatic CH donors. CrystEngComm 2011, 13, 5005–5010. [Google Scholar] [CrossRef]
  44. Manikandan, T.S.; Saranya, S.; Ramesh, R. Synthesis and catalytic evaluation of ruthenium(II) benzhydrazone complex in transfer hydrogenation of ketones. Tetrahedron Lett. 2016, 57, 3764–3769. [Google Scholar] [CrossRef]
  45. McGuiggan, M.F.; Pignolet, L.H. Synthesis and X-ray structural characterization of an ortho-metalated ruthenium complex of acetophenone. Inorg. Chem. 1982, 21, 2523–2526. [Google Scholar] [CrossRef]
  46. Flower, K.R.; Garrould, M.W.; Leal, L.G.; Mangold, C.; O’Malley, P.J.; Pritchard, R.G. The synthesis, reactivity and modelling studies of [RuCl(CO)(η2-C,O-C6H4-2-CHO)(PPh3)2]: Crystal and molecular structures of [RuCl(CO)(η2-C,O-C6H4-2-CHO)(PPh3)2]·3.5CHCl3 and [Ru(NCtBu)(CO)(η2-C,O-C6H4-2-CHO)(PPh3)2][BF4]·2CHCl3. J. Organomet. Chem. 2008, 693, 408–416. [Google Scholar] [CrossRef]
  47. Flower, K.R.; Leal, L.G.; Pritchard, R.G. Definitive proof of a Ru-Cl⋯ClCHCl interaction in the solid state: Crystal and molecular structure of [RuCl(CO)(η2-C,N-C6H4CH=NC6H4-4-Me)(PPh3)2]·CHCl3. Inorg. Chem. Commun. 2004, 7, 729–730. [Google Scholar] [CrossRef]
  48. Shivakumar, M.; Pramanik, K.; Ghosh, P.; Chakravorty, A. Isolation and structure of the first azo anion radical complexes of ruthenium. Inorg. Chem. 1998, 37, 5968–5969. [Google Scholar] [CrossRef] [PubMed]
  49. Cadierno, V.; Diez, J.; Garcia-Garrido, S.E.; Garcia-Granda, S.; Gimeno, J. Ruthenium(II) and ruthenium(IV) complexes containing hemilabile heterodifunctional iminophosphorane-phosphine ligands Ph2PCH2P(=NR)Ph2. J. Chem. Soc. Dalton Trans. 2002, 1465–1472. [Google Scholar] [CrossRef]
  50. Cadierno, V.; Crochet, P.; Diez, J.; Garcia-Alvarez, J.; Garcia-Garrido, S.E.; Gimeno, J.; Garcia-Granda, S.; Rodriguez, M.A. Ruthenium(II) and ruthenium(IV) complexes containing κ1-P-, κ2-P,O-, and κ3-P,N,O-iminophosphorane-phosphine ligands Ph2PCH2P{=NP(=O)(OR)2}Ph2 (R = Et, Ph):  synthesis, reactivity, theoretical studies, and catalytic activity in transfer hydrogenation of cyclohexanone. Inorg. Chem. 2003, 42, 3293–3307. [Google Scholar] [PubMed]
  51. Singh, T.; Kishan, R.; Nethaji, M.; Thirupathi, N. Synthesis, reactivity Studies, structural aspects, and solution behavior of half sandwich ruthenium(II) N,N′,N′′-triarylguanidinate complexes. Inorg. Chem. 2012, 51, 157–169. [Google Scholar] [CrossRef] [PubMed]
  52. Nongbri, S.L.; Das, B.; Rao, K.M. Arene ruthenium β-diketonato triazolato derivatives: Synthesis and spectral studies (β-diketones: 1-phenyl-3-methyl-4-benzoyl pyrazol-5-one, acetylacetone derivatives). J. Organomet. Chem. 2009, 694, 3881–3891. [Google Scholar] [CrossRef]
  53. Yadav, M.; Singh, A.K.; Maiti, B.; Pandey, D.S. Heteroleptic arene ruthenium complexes based on meso-substituted dipyrrins: Synthesis, structure, reactivity, and electrochemical studies. Inorg. Chem. 2009, 48, 7593–7603. [Google Scholar] [CrossRef] [PubMed]
  54. Singh, K.S.; Kreisel, K.A.; Yap, G.P.A.; Kollipara, M.R. Synthesis of arene ruthenium triazolato complexes by cycloaddition of the corresponding arene ruthenium azido complexes with activated alkynes or with fumaronitrile. J. Organomet. Chem. 2006, 691, 3509–3518. [Google Scholar] [CrossRef]
  55. Sheldirck, G.M. Area-Detector Absorption Correction (SADABS); Bruker AXS Inc.: Madison, WI, USA, 2004. [Google Scholar]
  56. Sheldrick, G.M. SHELX97-Programs for Crystal Structure Analysis: Structure Determination (SHELXS); University of Göttingen: Göttingen, Germany, 1997. [Google Scholar]
  57. Sheldrick, G.M. SHELX97-Programs for Crystal Structure Analysis: Refinement (SHELXL); University of Göttingen: Göttingen, Germany, 1997. [Google Scholar]
Sample Availability: Samples of the Compounds 2–5 are available from the authors.
Molecules 23 00159 sch001 550
Scheme 1. Synthesis of Compounds 2–5.
Scheme 1. Synthesis of Compounds 2–5.
Molecules 23 00159 sch001
Molecules 23 00159 g001 550
Figure 1. The molecular geometry of Compound 2. The thermal ellipsoids were drawn at 50% probability and all the hydrogen atoms except the methine proton on the cymene ring were omitted for clarity. The H8-O2 hydrogen bonding is shown.
Figure 1. The molecular geometry of Compound 2. The thermal ellipsoids were drawn at 50% probability and all the hydrogen atoms except the methine proton on the cymene ring were omitted for clarity. The H8-O2 hydrogen bonding is shown.
Molecules 23 00159 g001
Molecules 23 00159 g002 550
Figure 2. The molecular geometry of Compound 3. The thermal ellipsoids were drawn at 50% probability and all the hydrogen atoms were omitted for clarity.
Figure 2. The molecular geometry of Compound 3. The thermal ellipsoids were drawn at 50% probability and all the hydrogen atoms were omitted for clarity.
Molecules 23 00159 g002
Molecules 23 00159 g003 550
Figure 3. The molecular geometry of Compound 4. The thermal ellipsoids were drawn at 50% probability and all the hydrogen atoms were omitted for clarity.
Figure 3. The molecular geometry of Compound 4. The thermal ellipsoids were drawn at 50% probability and all the hydrogen atoms were omitted for clarity.
Molecules 23 00159 g003
Molecules 23 00159 g004 550
Figure 4. The molecular geometry of Compound 5. The thermal ellipsoids were drawn at 50% probability and all the hydrogen atoms except the methine proton on the cymene ring were omitted for clarity. The H8-O2 hydrogen bonding is shown.
Figure 4. The molecular geometry of Compound 5. The thermal ellipsoids were drawn at 50% probability and all the hydrogen atoms except the methine proton on the cymene ring were omitted for clarity. The H8-O2 hydrogen bonding is shown.
Molecules 23 00159 g004
Table
Table 1. The summary of X-ray crystal data for Compounds 2–5.
Table 1. The summary of X-ray crystal data for Compounds 2–5.
23 THF45
formulaC22H24ClNO2RuC53H48ClNO4P2RuC23H24N2O3RuC22H24N4O2Ru
FW470.94961.38477.51477.52
T [K]150(2)150(2)150(2)150(2)
crystal systemMonoclinicMonoclinicMonoclinicMonoclinic
space groupP21/nP21/nP21/cP21/c
a [Å]10.4657(4) 10.2279(5)10.157(5)17.3849(14)
b [Å]9.1505(3) 17.5822(9)15.836(7)9.2423(7)
c [Å]21.1478(8) 25.9234(13)14.019(8)13.8157(11)
α [°]90909090
β [°]99.097(2)97.693(3)105.44(3)112.379(4)
γ [°]90909090
V [Å3]1999.78(13)4619.8(4)2173.5(19)2052.7(3)
Z4444
ρc [Mg m−3]1.5641.3821.4651.545
μ [mm−1]0.9340.5130.7480.787
F(000)9601824980976.0
rflns collected28,62949,63326,43918,124
independent rflns5176 [Rint = 0.0263]8132 [Rint = 0.0979]5380 [Rint = 0.0893]5243 [Rint = 0.0298]
data/restraints/parameters5176/0/2488132/0/5605380/0/2665243/0/266
goodness-of-fit on F21.0270.8800.9681.067
R1, wR2 (I > 2σ(I))R1 = 0.0208R1 = 0.0591R1 = 0.0568R1 = 0.0306
wR2 = 0.0494wR2 = 0.1682wR2 = 0.1449wR2 = 0.0783
R1, wR2 (all data)R1 = 0.0260R1 = 0.0879R1 = 0.0890R1 = 0.0356
wR2 = 0.0520wR2 = 0.1925wR2 = 0.1724wR2 = 0.0810
largest diff. peak, hole [eÅ−3]0.406 and −0.3670.811 and −0.9251.071 and −2.0140.870 and −0.699
Table
Table 2. Selected bond lengths (Å) and angles (°) for Compounds 2–5.
Table 2. Selected bond lengths (Å) and angles (°) for Compounds 2–5.
2
Ru(1)-Cl(1)2.4092(5)Ru(1)-N(1)2.060(1)
Ru(1)-O(1)2.103(1)Ru(1)-Cymene1.6598(1)
O(1)-C(15)1.273(2)N(1)-Ru(1)-O(1)77.09(5)
Cl(1)-Ru(1)-N(1)85.41(4)Cl(1)-Ru(1)-O(1)85.53(3)
3
Ru(1)-C(50)1.845(7)Ru(1)-N(1)2.038(5)
Ru(1)-O(1)2.139(4)Ru(1)-P(1)2.4058(15)
O(1)-C(15)1.273(2)Ru(1)-P(2)2.3908(15)
Ru(1)-Cymene1.6598(1)Ru(1)-Cl(1)2.4185(15)
O(1)-C(41)1.280(7)C(50)-O(4)1.128(8)
C(50)-Ru(1)-O(1)172.9(2)P(2)-Ru(1)-P(1)177.38(5)
N(1)-Ru(1)-Cl(1)166.70(14)N(1)-Ru(1)-O(1)78.32(16)
4
Ru(1)-N(1)2.070(5)Ru(1)-N(2)2.057(3)
Ru(1)-O(2)2.124(3)Ru(1)-Cymene1.6674(7)
O(2)-C(5)1.278(5)N(1)-C(23)1.155(6)
O(1)-C(23)1.218(6)Ru(1)-N(1)-C(23)156.9(4)
N(1)-Ru(1)-N(2)84.53(16)N(2)-Ru(1)-O(2)77.03(13)
N(1)-Ru(1)-O(2)83.61(16)N(1)-C(23)-O(1)176.3(6)
5
Ru(1)-N(1)2.109(2)Ru(1)-N(2)2.0640(19)
Ru(1)-O(1)2.1114(15)Ru(1)-Cymene1.6610(2)
O(1)-C(15)1.276(3)N(1)-N(2)1.204(3)
N(2)-N(3)1.157(3)N(4)-Ru(1)-O(1)77.08(7)
N(1)-Ru(1)-N(4)86.02(8)N(1)-Ru(1)-O(1)86.62(7)
Ru(1)-N(1)-N(2)120.43(17)N(1)-N(2)-N(3)176.7(3)

Share and Cite

MDPI and ACS Style

Tsai, Y.-W.; Chen, Y.-F.; Li, Y.-J.; Chen, K.-H.; Lin, C.-H.; Huang, J.-H. Structural Determination of Ruthenium Complexes Containing Bi-Dentate Pyrrole-Ketone Ligands. Molecules 2018, 23, 159. https://doi.org/10.3390/molecules23010159

AMA Style

Tsai Y-W, Chen Y-F, Li Y-J, Chen K-H, Lin C-H, Huang J-H. Structural Determination of Ruthenium Complexes Containing Bi-Dentate Pyrrole-Ketone Ligands. Molecules. 2018; 23(1):159. https://doi.org/10.3390/molecules23010159

Chicago/Turabian Style

Tsai, Ya-Wen, Yun-Fan Chen, Yong-Jie Li, Kuan-Hung Chen, Chia-Her Lin, and Jui-Hsien Huang. 2018. "Structural Determination of Ruthenium Complexes Containing Bi-Dentate Pyrrole-Ketone Ligands" Molecules 23, no. 1: 159. https://doi.org/10.3390/molecules23010159

Article Metrics

Back to TopTop